Abstract Format : Retention is an important stage of the HIV care cascade providing opportunities to monitor antiretroviral therapy adherence, prevent HIV-associated complications and deliver ancillary services that improve overall survival and reduce HIV transmission. Furthermore, more recent evidence suggests that certain factors can act as both barriers and facilitators to retention, depending on the context. It is also important to understand how these factors impact retention individually and in combination with each other. According to the Andersen-Newman Framework for Health Services Utilization, factors influencing health-seeking behaviours and utilization of care can be defined as 1) predisposing characteristics (socio-cultural characteristics of individuals), 2) enabling resources (the logistical aspects of obtaining care), and 3) need factors (the most immediate cause of healthcare use, arising from problems that generate the need for care). This framework has previously been used successfully to identify factors affecting retention in HIV care and has been helpful for informing the development of interventions and strategies to improve retention in care. This systematic review applies the Andersen-Newman framework and aims to identify and synthesize quantitative evidence examining factors associated with retention in HIV care in high-income settings, with focus on those factors that act as both barriers and facilitators.

Methods : Searches were conducted in MEDLINE, EMBASE and PsycInfo in July 2015. Articles published since 1996 were included. Quantitative studies with retention in HIV care defined as an outcome were included. We considered studies using broad definitions of retention although we excluded those that used laboratory measures to define retention. Studies focusing on children, youth, transitioning into and out of prison, and transitioning between pre- and post-natal care were excluded. Screening, data extraction, and quality assessments were completed by two independent reviewers. Only quantitative studies with statistically-adjusted data were included in this analysis.

Results : A total of 5,521 citations were identified, of which 62 quantitative studies (57 cross-sectional and 5 cohort studies) met the inclusion criteria. The majority of studies (n=48, 77%) were conducted in the United States. Forty-three (69.4%) studies reported barriers and/or facilitators to retention that were predisposing characteristics; three factors were both positively and negatively associated with retention in care: being female, Hispanic identity, and heterosexual route of transmission. Forty-one (66.1%) studies reported enabling resources as barriers and/or facilitators to retention; findings were mixed among the seven studies that explored the association between type of health insurance and retention in HIV care. Forty-four (71.0%) studies identified need factors associated with retention, and mixed findings were noted for CD4 count and among studies that explored mental health.

Conclusions : This systematic review identified predisposing characteristics, enabling resources, and need factors that demonstrated mixed findings with respect to retention in HIV care. Findings suggest that context matters when individuals living with HIV engage or do not engage continuously in HIV care. When considering the design of interventions to improve retention in HIV care, public health professionals may want to consider that certain factors may work to impede or facilitate retention in HIV care, depending on the context. This review was limited to studies based in high-income settings, so findings may not be generalizable to low- and middle-income settings. Additionally, the majority of included studies were cross-sectional in design, limiting the ability to establish causality.